Basket catheter and electrode assemblies configured for improved tissue contact

Abstract

To provide a basket catheter assembly.SOLUTION: The disclosed technology includes an end effector comprising a plurality of spines extending along a longitudinal axis to define a basket assembly, the plurality of spines configured to bow radially outward from the longitudinal axis to define a radius of curvature with respect to the longitudinal axis and to transition between an expanded configuration and a collapsed configuration. Each spine of the plurality of spines can include a section extending radially outward from the radius of curvature defined by a remainder of each spine. The end effector can further include at least one electrode disposed on the section for each spine of the plurality of spines.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims the benefit of priority under 35 U.S.C. § 119 to prior - filed U.S. Provisional Patent Application No. 63 / 615,210, filed on December 27, 2023 (Attorney Docket No.: 253757.000194 (BIO6733USPSP1)), the entire content of which is incorporated herein by reference as if fully set forth herein.

[0002] (Field of the Invention) The present invention generally relates to basket catheter assemblies, and more specifically to basket catheter assemblies having spring - loaded electrodes disposed on a spine and configured for improved tissue contact.

Background Art

[0003] Basket catheters are commonly used for mapping and ablation of myocardial tissue. Intravascular catheters typically include an end - effector having one or more electrodes configured to receive electrical signals from tissue for mapping and / or deliver ablation energy to tissue ablation. To ensure that the electrodes are accurately positioned for mapping or ablation, some end - effectors include position sensing such as electromagnetic position sensing or active current location (ACL) technology. This position sensing technology can also be used to detect the quality of contact between the ablation electrode and the target tissue.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In some existing catheters, the catheter includes a spine configured to bend radially outward to contact the electrode with tissue. The spine is generally configured with a uniform radius of curvature along all or most of the spine. Since the radius of curvature of the spine is uniform, when the basket catheter contacts the target tissue, further portions of the spine on either side of the electrode also contact the target tissue. When determining the position of such an electrode, the user may not be able to obtain sufficiently detailed information regarding the force applied to the electrode that is remote from the spine. As will be appreciated, it is desirable to obtain accurate data regarding the force applied to the electrode as well as the location of the individual electrodes. Accordingly, there is a need in the art for a method to improve the detectability of electrode tissue contact while also obtaining accurate force data. The techniques of the present disclosure address these and other problems herein.

Means for Solving the Problems

[0005] According to one embodiment of the present disclosure, an end effector for a medical device is provided that includes a plurality of spines extending along a longitudinal axis and defining a basket assembly. The plurality of spines can be configured to bend radially outward from the longitudinal axis to define a radius of curvature relative to the longitudinal axis and to transition between an expanded configuration and a folded configuration. Each of the plurality of spines can include a section that extends radially outward from a radius of curvature defined by the remainder of each spine. The end effector can further include at least one electrode disposed on the section for each of the plurality of spines.

[0006] The techniques of the present disclosure can include an electrode assembly comprising an electrode body extending along a longitudinal axis and defining a recess, and an electrode cap at least partially disposed within the recess. The electrode assembly can further include a spring member disposed within the recess between the electrode body and the electrode cap and configured to expand the electrode cap outwardly from the electrode body.

[0007] Additional features, functions, and applications of the technology of the present disclosure are discussed in more detail herein.

Brief Description of the Drawings

[0008]

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DETAILED DESCRIPTION OF THE INVENTION

[0009] The technology of the present disclosure includes a basket catheter that can be configured for ablation and / or mapping. As will become apparent through the present disclosure, the spine and electrode configuration of the basket catheter can be configured to help improve tissue contact of the electrodes. The technology of the present disclosure also includes an improved method for detecting the force applied to each electrode and the position of each electrode. In some examples, the spine can include a biasing section that contacts the tissue with electrodes disposed along the biasing section before the remainder of the spine contacts the tissue. This helps ensure that the desired portion of the spine first contacts the target tissue and overall electrode surface contact is improved. In other embodiments, the spine can include position sensors and / or strain gauges disposed along the spine for obtaining position and force data associated with the electrodes.

[0010] The techniques of the present disclosure also include an electrode assembly configured to detect contact forces and the position of each individual electrode. For example, the electrode assembly can each include sensors for determining the forces applied to the electrode assembly as well as the position and orientation of the electrodes. That is, the sensors described herein enable determination of the location of the electrodes as well as the direction of the forces applied to the electrodes. This is accomplished through determination of the location of the magnetic coils (which gives the location of the electrodes), and knowing the displacement of one of the magnetic coils relative to another magnetic coil coupled to a spring (having a known spring constant) between the two magnetic coils enables determination of the force and its vector.

[0011] The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered the same. The drawings are not necessarily to scale, depict selected embodiments, and are not intended to limit the scope of the invention. The detailed description is by way of example, not limitation, and illustrates the principles of the invention. This description enables one skilled in the art to make and use the invention and describes some embodiments, adaptations, variations, alternatives, and uses of the invention, including what is presently considered to be the best mode of carrying out the invention.

[0012] As used herein, the terms “about” or “substantially” with respect to any numerical value or range indicate a suitable dimensional tolerance that allows a component or collection of components to function for the intended purpose described herein. More specifically, “about” or “substantially” can refer to a range of values that are ±20% of the recited value. For example, “about 90%” can refer to a range of values from 71% to 110%. Additionally, as used herein, the terms “patient,” “host,” “user,” and “subject” refer to any human or animal subject, and while use of the invention in human patients represents a preferred embodiment, it is not intended to limit the system or method to human use. Similarly, the term “proximal” indicates the location closer to the operator or physician, while “distal” indicates the location farther from the operator or physician.

[0013] As discussed herein, the vasculature of "patient", "host", "user", and "subject" can be that of a human or any animal. It should be understood that the animal can be of any of a variety of applicable types, including but not limited to mammals, veterinary animals, livestock animals, or pet animals. By way of example, the animal can be a laboratory animal (e.g., rat, dog, pig, monkey, etc.) specifically selected to have certain properties similar to those of a human. It should be understood that the subject can be, for example, any applicable human patient.

[0014] As discussed herein, "physician" can include a physician, surgeon, technician, scientist, operator, or any other individual or delivery device associated with the delivery of a multi-electrode catheter for the treatment of drug-refractory atrial fibrillation to a subject.

[0015] As discussed herein, the terms "ablating" or "ablation," when referring to the devices and corresponding systems of the present disclosure, refer to components and structural features configured to reduce or prevent the generation of irregular cardiac signals within cells, throughout the present disclosure, by utilizing non-thermal energy such as reversible electroporation or irreversible electroporation (IRE), which are interchangeably referred to as pulsed electric field (PEF) and pulsed field ablation (PFA), or thermal energy such as radiofrequency (RF) ablation or cryoablation. When referring to the devices and corresponding systems of the present disclosure, ablating or ablation is used throughout the present disclosure with reference to thermal or non-thermal ablation of cardiac tissue in certain conditions, including but not limited to arrhythmias, atrial fibrillation ablation, pulmonary vein isolation, supraventricular tachycardia ablation, and ventricular tachycardia ablation. The terms "ablating" or "ablation" also include known methods, devices, and systems for achieving various forms of body tissue ablation, as would be understood by one of ordinary skill in the art.

[0016] As discussed herein, the terms "tubular" and "tube" are to be construed broadly and are not limited to a straight cylindrical structure, or a structure with a strictly circular cross-section, or a structure with a uniform cross-section throughout its length. For example, a tubular structure is generally illustrated as a substantially straight cylindrical structure. However, a tubular structure may have a tapered or curved outer or inner surface without departing from the scope of the present disclosure.

[0017] Refer to FIG. 1 showing an exemplary catheter-based electrophysiological mapping and ablation system 10. System 10 includes a plurality of catheters that are percutaneously inserted by a physician 24 through the vasculature of a patient 23 into a chamber or vascular structure of the heart 12. Typically, a delivery sheath catheter is inserted into the left atrium or right atrium near a desired location in the heart 12. Thereafter, a plurality of catheters can be inserted into the delivery sheath catheter to reach the desired location. The plurality of catheters can include catheters dedicated to sensing intracardiac electrogram (IEGM) signals, catheters dedicated to ablation, and / or catheters dedicated to both sensing and ablation. To sense the IEGM, the physician 24 contacts the distal tip 28 of the catheter 14 with the heart wall to sense the target site of the heart 12. The end effector of the mapping catheter can include a basket catheter, a planar catheter, a focus catheter, a balloon catheter, and the like. For ablation, the physician 24 similarly moves the distal end of the ablation catheter to the target site for ablation (as shown in the inset of FIG. 1). Similarly, the end effector of the ablation catheter can include a basket catheter, a planar catheter, a focus catheter, a balloon catheter, and the like.

[0018] Catheter 14 is an exemplary catheter that includes one, preferably a plurality of electrode assemblies 26 that are optionally distributed across a plurality of spines 22 at the distal tip 28 and configured to deliver ablation energy to tissue. Catheter 14 can additionally include a position sensor 29 embedded within or near the distal tip 28 to track the position and orientation of the distal tip 28. Optionally and preferably, the position sensor 29 is a magnetic-based position sensor that includes three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0019] The magnetic-based position sensor 29 can operate with a location pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field within a predetermined working volume. The real-time position of the distal tip 28 of the catheter 14 can be tracked based on the magnetic field generated by the location pad 25 and sensed by the magnetic-based position sensor 29. Details of magnetic-based position sensing techniques are described in U.S. Patent Nos. 5,391,199, 5,443,489, 5,558,091, 6,172,499, 6,239,724, 6,332,089, 6,484,118, 6,618,612, 6,690,963, 6,788,967, 6,892,091, and the entireties of each of these are incorporated herein by reference. Sensors that provide both contact force and position information via magnetic location technology are illustrated and described in U.S. Patent Nos. 8,437,832, 8,535,308, 8,784,413, and 8,357,152, and the entireties of each of these are incorporated herein by reference and are attached to the appendix of this specification.

[0020] The system 10 includes one or more electrode patches 38 positioned for skin contact on the patient 23 to establish a location reference for the location pad 25 and impedance-based tracking of the electrode assembly 26. For impedance-based tracking, a current is directed to the electrode assembly 26 and sensed at the electrode skin patches 38, whereby the location of each electrode can be triangulated via the electrode patches 38. Details of impedance-based location tracking techniques are described in U.S. Patent Nos. 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182, and the entireties of each of these are incorporated herein by reference.

[0021] Recorder 11 displays the electrocardiogram 21 captured by the body surface ECG electrodes 18 and the intracardiac electrogram (IEGM) captured by the electrode assembly 26 of the catheter 14. Recorder 11 may include pacing capabilities for pacing the rhythm of the heart and / or may be electrically connected to an independent pacer.

[0022] System 10 may include an ablation energy generator 50 adapted to deliver ablation energy to one or more of the electrodes at the distal tip of a catheter configured to ablate. The energy generated by ablation energy generator 50 may include high frequency (RF) energy or pulsed field ablation (PFA) energy, or a combination thereof, including unipolar or bipolar high voltage DC pulses that may be used to effect irreversible electroporation (IRE), but is not limited thereto.

[0023] Patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheter, the electrophysiology equipment, the power source, and the workstation 55 that controls the operation of system 10. The electrophysiology equipment of system 10 may include, for example, a plurality of catheters, location pads 25, body surface ECG electrodes 18, electrode patches 38, ablation energy generator 50, and recorder 11. Optionally and preferably, PIU 30 additionally includes processing capabilities for implementing real-time calculation of the location of the catheter and performing ECG calculations.

[0024] The workstation 55 includes a memory, a processor unit having a memory or storage device loaded with appropriate operating software, and a user interface function. The workstation 55 optionally provides a plurality of functions including: (1) modeling the endocardial anatomical structure in three dimensions (3D) and rendering it to display a model or anatomical map 20 on a display device 27; (2) displaying on the display device 27, in a representative visual display or image superimposed on the rendered anatomical map 20, an activation sequence (or other data) compiled from the recorded electrogram 21; (3) displaying the real-time location and orientation of a plurality of catheters within the heart chamber; and (4) displaying on the display device 27 a site of interest such as a location where ablation energy is being applied. One commercially available product embodying the elements of the system 10 is available as the CARTO (trademark) 3 system, marketed by Biosense Webster, Inc. (31 Technology Drive, Suite 200, Irvine, CA 92618, USA).

[0025] FIG. 2A is a schematic illustrative diagram showing a perspective view of a catheter 14 having an end effector 28 which is a basket assembly in an expanded configuration when not constrained, such as by being advanced from the tubular shaft lumen 80 at the distal end 85 of the tubular shaft 82 (as depicted in FIG. 2B). FIG. 2B shows the basket assembly in a folded configuration within the tubular shaft 82. In the expanded configuration (FIG. 2A), the spine 22 bends radially outward along the longitudinal axis 86, and in the folded configuration (FIG. 2B), the spine is constrained generally along the longitudinal axis 86 of the tubular shaft 82 by the inner wall of the tubular shaft 82.

[0026] As shown in FIG. 2A, the basket assembly 28 (referred to interchangeably herein as the “distal tip”) is formed at the end of the flexible shaft 84 and includes a plurality of flexible spines 22 connected at both ends. During a medical procedure, the physician 24 can deploy the basket assembly 28 by extending the flexible shaft 84 from the tubular shaft 82 and moving the basket assembly 28 out of the tubular shaft 82 and into an expanded configuration. The spines 22 can have an elliptical (e.g., circular) or rectangular (which may appear flat) cross-section and can include a flexible elastic material (e.g., a shape memory alloy such as nickel-titanium, also known as nitinol) that forms struts, as described in more detail herein.

[0027] In the embodiments described herein, the electrode assembly 26 can be configured to deliver ablation energy (RF and / or IRE) to tissue within the heart 12 or other parts of the patient 23's body. In addition to using the electrode assembly 26 to deliver ablation energy, the electrode assembly can also be used to measure physiological properties such as local surface potentials at respective locations on tissue within the heart 12 (e.g., IEGM signals). The electrode assembly 26 can be biased such that a larger surface area of the electrode body of the electrode assembly 26 faces outward from the basket assembly 28, whereby the electrode assembly 26 delivers a large amount of electrical energy outwardly (i.e., toward the tissue of the heart 12) away from the basket assembly 28 rather than inwardly toward the longitudinal axis 86 of the basket assembly 28. The basket assembly 28 can include a stem 96 that extends longitudinally from the distal end 90 of the flexible shaft 84 toward the distal end 212 of the basket assembly 28. The basket assembly 28 can include a central intersection 211 at a point where the spines 22 converge near the distal end 212.

[0028] Referring now to FIG. 3, an exemplary end effector 28 in an extended configuration is illustrated. The end effector 28 can be configured to transition between an extended configuration and a folded configuration. For example, the spine 22 can include nitinol, which can be heat set to a predetermined shape (e.g., the deployed configuration) such that when the spine 22 is inserted into the blood pool at a predetermined temperature, the spine 22 transitions to a heat set deployed configuration. In some examples, each of the plurality of spines 22 can be covered in a layer of biocompatible insulating material. The end effector 28 can include a plurality of spines 22, and each of the plurality of spines 22 extends along a longitudinal axis 86 and bends radially outward from the longitudinal axis 86 to define a radius of curvature 328 relative to the longitudinal axis 86 and is configured to form a basket shape.

[0029] As shown in FIG. 3, each of the plurality of spines 22 can further include a plurality of electrodes 26 disposed on each spine 22. The electrodes 26 can be disposed on each spine 22 such that the electrodes 26 of adjacent spines 22 are not horizontally aligned, but instead are staggered relative to each other. For example, the electrode 26A of spine 22A is not horizontally aligned with the electrode 26B of spine 22B. The end effector 28 can further include a central position sensor 342 attached to a central delivery shaft 340, the central delivery shaft 340 being positioned within the center of the end effector 28 and emerging from where the spines 22 of the plurality of spines 22 converge proximally. In other examples, the central position sensor 342 can be disposed on the stem 96.

[0030] As shown, each of the plurality of spines 22 can include a biasing section 320 that extends radially outward from a radius of curvature 328 defined by the remainder of each spine 22. This biasing section 320 can bring the electrode 26 into contact with the target tissue before the remainder of each of the plurality of spines 22 contacts the tissue. In other words, the biasing section 320 can be configured to dispose the electrode 26 further away from the longitudinal axis 86 so that the electrode 26 is more likely to contact the tissue before other parts of the end effector 28. As will be appreciated, this can help ensure that the electrode 26 makes sufficient contact with the tissue.

[0031] In some examples, as shown in more detail in FIGS. 6A-6B, the spine 22 can further include a position sensor 650 disposed in each biasing section 320 of each spine 22. The location sensor 650 can be disposed, for example, under or on both sides of each respective electrode 26, as shown in FIG. 6A. As described above, the end effector 28 can include a central position sensor 342 disposed at the center within the end effector 28. This can be used in conjunction with the location sensor 650 disposed in the biasing section 320 to determine the amount of deflection the spine 22 undergoes. Using this information, the magnitude and direction of the force applied to the end effector 28 can be determined. For example, if the spring constant of the biasing section 320 is known, that information can be used, along with the detected locations of the electrodes 26A, 26B disposed on the biasing section 320, relative to each other and relative to the central position sensor 342, to determine the magnitude and direction of the force received by the electrode 26. As a result, a detailed image of both the magnitude and direction of the force exerted on the end effector 28 can be calculated.

[0032] For purposes of illustration, when the basket assembly 28 is brought into contact with tissue on a first side, the electrode 26 on that first side is pushed inwardly toward the central position sensor 342, and the electrode 26 on the second, opposite side is pushed outwardly away from the central position sensor 342. In addition to the spring constant of the spine 22, by knowing the position of the electrode 26 relative to the central position sensor 342, the magnitude and direction of the force applied to the basket assembly 28 can be determined. Similarly, coils disposed on the electrodes can be used to determine the location of the electrodes in free space that are triangulated via an external magnetic field generator.

[0033] Referring now to FIGS. 4A-4B, an alternative end effector 28 is illustrated that includes a plurality of spines 22 that define a basket shape in an expanded configuration, but does not include a central position sensor 342. As described above, each of the plurality of spines 22 can extend along a longitudinal axis 86 and can be configured to bend radially outwardly away from the longitudinal axis 86 when the end effector 28 is in the expanded configuration. Each of the plurality of spines 22 can be configured to converge at a central intersection 211 that defines the distal end of the end effector 28. Further, the plurality of spines 22 can include a plurality of electrodes 26 disposed along the spine in a biasing section 320 of the spine 22.

[0034] Referring now to FIGS. 5A - 5B, which illustrate an electrode 26 configured to be disposed along a spine 22 of a basket catheter. The electrode 26 can include an electrode body 532 that defines a lumen 534 configured to receive the spine 22. In other words, the electrode 26 can be configured to slide over the spine 22. The electrode 26 can further include an electrode surface 530 configured to contact target tissue within an organ 12 of a patient 23. In some examples, the electrode body 532 can include an insulating material to ensure that ablation energy is delivered only through the electrode surface 530 and to shield the electrode body 532 from ablation energy, while the electrode surface 530 is not insulated. In other examples, the entire electrode 26 can be conductive.

[0035] FIG. 6A illustrates an alternative end effector 28 in an expanded configuration. The end effector 28 can include a plurality of spines 22 that extend along a longitudinal axis 86 and define a basket shape when the end effector 28 is in the expanded configuration. In some examples, at least some of the plurality of spines 22 can include position sensors 650 disposed along the spines 22. Similar to the end effector 28 shown in FIG. 3, each of the plurality of spines 22 can be configured to bend radially outward from the longitudinal axis 86 to define a radius of curvature 328 for each spine 22. Each spine can further include a biasing section 320 that extends radially outward from the radius of curvature 328 defined by the remainder of each spine 22.

[0036] As described above, a plurality of position sensors 650 can be disposed along the spine 22. For example, the position sensors 650 can be disposed on the spine 22 in each biasing section 22A, 22B of each spine 22 such that the position sensors 650 are positioned under or beside the electrodes 26. In some examples, the end effector 28 can include a plurality of position sensors 650A - 650C disposed in each biasing section 22A, 22B of each spine 22. As shown in FIG. 6B, the plurality of position sensors 650A - 650C can include at least three position sensors 650A - 650C positioned approximately 60 degrees from each other so as to form a triaxial sensor. As will be appreciated, the position data collected by the triaxial sensor can be used to more accurately determine the location and orientation of each biasing portion 320 of each spine 22.

[0037] As yet another example, the end effector 28 can alternatively include one strain gauge or a plurality of strain gauges disposed on the biasing section 320 of the spine 22 as shown and described in connection with FIG. 11B. The strain gauge can likewise be used to determine the amount of force received by the biasing section 320 of the spine 22 since it detects the strain applied to the spine 22. Next, this force data can be used to determine the amount of force applied to each electrode 26.

[0038] Referring now to FIG. 7, an alternative end effector 728 in an extended configuration is illustrated. The end effector 728 can include a plurality of spines 722 that extend along a longitudinal axis 86 and define a basket shape when the end effector 728 is in the extended configuration. The spines 722 can be configured to bend radially outward from the longitudinal axis 86 of the end effector 728. Further, the spines 722 can be configured to converge at a central intersection 711 and to define a distal end 712 of the end effector 728. Each spine 722 can include one or more electrode assemblies 726 disposed along the spine 722. As described above, each electrode assembly 726 can be positioned along the spine 726 in a biasing section 722 of each spine 722. Alternatively, the spine 22 may not include a biasing section, but the electrode assembly 726 can be configured such that an outward facing portion (the portion of the electrode assembly 726 facing away from the longitudinal axis 86) can be larger than an inward facing portion (the portion of the electrode assembly 726 facing toward the longitudinal axis 86). The electrode assembly 726 of each electrode assembly 726 can further include an electromagnetic coil 770 disposed on an inward facing side of an electrode body 740, as will be described in more detail in FIG. 11C.

[0039] Referring now to FIGS. 8A-8D, an electrode assembly 726 disposed along the spine 722 illustrated in FIG. 7 is illustrated. The electrode assembly 726 can include an electrode body 740, an electrode cap 742, and a lumen 744 extending through the electrode body 740 and configured to receive the spine 722. The electrode cap 742 can be positioned at the center of the uppermost surface of the electrode body 740, as shown in FIG. 8B. The electrode body 740 can define cutouts 746 at respective ends of the lumen 744, as shown in FIG. 8C. This allows the electrode assembly 726 to fully receive the spine 722 and allows the spine 722 to bend. In some examples, the electrodes illustrated in FIGS. 8A-8D can be disposed not only on the basket catheter as shown in FIG. 7, but also on an end effector 28 having a biasing section 320 similar to that illustrated in FIGS. 3-4B. FIGS. 9-11C further illustrate details of these electrode assemblies 726.

[0040] Figs. 9-10 illustrate an exemplary electrode assembly 726 similar to the electrode assembly 726 illustrated in Figs. 8A-8D. As can be seen from Fig. 9, which is a cross-sectional view of the electrode assembly 726 along line A-A shown in Fig. 8B, the electrode assembly 726 can include an electrode body 740 and an electrode cap 742 disposed within a recess 748 defined by the electrode body 740. As described previously, the electrode body 740 can include a lumen 744 that extends through the electrode body 740 and is configured to receive the spine 722 of the end effector 728. The recess 748 of the electrode body 740 can include a spring member 750 disposed within the recess 748 between the electrode body 740 and the electrode cap 742. The electrode assembly 726 can further include a sensor assembly 761. The sensor assembly 761 has a movable coil 760, an elastic member 750 coupled to the first coil 760, and a fixed coil 762. The fixed coil 762 can be connected to a Biosense Webster Carto3 system to transmit a magnetic field of a predetermined frequency, and the movable coil 760 can be configured to receive a transmitted magnetic field that induces a current within the movable coil 760. The induced current within the movable coil 760 can be used by Carto3 to determine the location of the movable coil or sensor 760 relative to the fixed coil or sensor 762. At least one position sensor or coil 760 can be disposed within the electrode cap 742, and at least one position sensor or coil 762 can be disposed within the electrode body 740 between the lumen 744 and the recess 748.

[0041] In some examples, the spring member 750 can be configured to apply a force to the electrode cap 742 that causes the electrode cap 740 to extend outwardly away from the electrode body 740. As shown in FIG. 10, the recess 748 of the electrode body 740 can include a lip 749 that extends around the recess 748, and the electrode cap 740 can include an edge 743 that extends around the circumference of the electrode cap 742. The lip 749 of the recess 748 can be configured to assist in holding the electrode cap 740 on the electrode body 740. For example, the edge 743 of the electrode cap 740 can slide along the lip 749 but be configured not to be removed from the lip 749 to prevent removal of the electrode cap 740. The spring member 750 and the position sensors 760, 762 can be used together, for example, to calculate the amount of force applied to the electrode assembly 726 when the electrode assembly 726 is brought into contact with tissue. For example, if the spring constant of the spring member 750 is known, the techniques of the present disclosure can determine the displacement of the position sensor 760 in the electrode cap 742 relative to the position sensor 762 in the electrode body 740 and correlate the displacement to the spring constant of the spring member 750 to determine the force applied to the electrode cap 742. In this way, the amount of force applied to each electrode assembly 726 can be determined and output for visual inspection by a physician.

[0042] Referring now to FIG. 11A, a spring member 750 that can be disposed within the electrode assembly 726 illustrated in FIGS. 7-10 is illustrated. In some examples, the spring member 750 can alternatively or additionally include a strain gauge 752 disposed on the spring member 750. The strain gauge 752 can be configured to determine the amount of force applied by the spring member 750 to the electrode cap 742. In some examples, the spring member 750 further includes three strain gauges 752A-752C that are disposed on the spring member 750 and are spaced approximately 60 degrees apart from each other, as shown in FIG. 11B, to determine the magnitude and direction of the force applied to the electrode cap 742. In some examples, the strain gauges 752A-752C can include a flexible circuit configured to detect strain when bent.

[0043] FIG. 11C illustrates a bottom view of the electrode body 740. In this example, the electrode body 740 can include one or more electromagnetic coils 770 disposed on the lower side of the electrode body 740. In some examples, the electromagnetic coils 770 of the electrode body 740 can include first and second electromagnetic coils 770 that can form a biaxial sensor. In other examples, the electrode body 740 can include only one electromagnetic coil, or more than two electromagnetic coils, or any number of electromagnetic coils suitable for a particular application. Each electromagnetic coil 770 can be configured to output a current when receiving an electromagnetic field and to detect the position of the electrode assembly 726. As will be appreciated, by including one or more electromagnetic coils 770 on the electrode assembly 726, the techniques of the present disclosure can be configured to determine the position and orientation of each electrode assembly 726 on the basket catheter 728.

[0044] The techniques of the present disclosure described herein can be further understood in accordance with the following clauses.

[0045] Clause 1. An end effector for a medical device, comprising a plurality of spines extending along a longitudinal axis and defining a basket assembly, the spines being bent radially outward from the longitudinal axis so as to define a radius of curvature with respect to the longitudinal axis and being configured to transition between an expanded configuration and a folded configuration, each spine of the plurality of spines including a section extending radially outward from a radius of curvature defined by the remainder of the spine, a plurality of spines, and at least one electrode disposed on a spring biasing section for each spine of the plurality of spines.

[0046] Clause 2. The end effector according to clause 1, wherein a plurality of electrodes are disposed on each spine of the plurality of spines.

[0047] Clause 3. The end effector according to clause 1, wherein each electrode of the plurality of electrodes is disposed on a respective section on each spine of the plurality of spines.

[0048] Clause 4. The end effector according to clause 3, wherein the section of each spine of the plurality of spines is configured to bring each respective electrode of the plurality of electrodes into contact with tissue before the remainder of each spine contacts the tissue when the end effector is brought into contact with the tissue.

[0049] Clause 5. The end effector according to clause 1, wherein at least one electrode is configured to deliver ablation energy to tissue.

[0050] Clause 6. The end effector according to clause 3, further comprising a location sensor disposed on each respective section and configured to detect the location of the section.

[0051] Clause 7. The end effector according to clause 6, wherein each location sensor is disposed on a section under each respective electrode of the plurality of electrodes.

[0052] Clause 8. The end effector according to Clause 1, comprising: an electrode body defining a lumen and a recess extending through the electrode body; an electrode cap disposed at least partially within the recess; and a spring member disposed within the recess between the electrode body and the electrode cap and configured to expand the electrode cap outwardly from the electrode body.

[0053] Clause 9. The end effector according to Clause 8, further comprising a sensor coupled to the spring member and configured to detect a force applied to the electrode.

[0054] Clause 10. The end effector according to Clause 8, wherein the electrode body further defines a lip extending around the recess, the lip being configured to prevent the electrode cap from being removed from the recess.

[0055] Clause 11. The end effector according to Clause 8, wherein the lumen is configured to receive a spine of a plurality of spines.

[0056] Clause 12. The end effector according to Clause 8, further comprising a position sensor disposed on the electrode body and configured to output a current when receiving an electromagnetic field to detect the position of the electrode.

[0057] Clause 13. The end effector according to Clause 12, wherein the position sensor is disposed on a side facing the inside of the electrode body facing the longitudinal axis.

[0058] Clause 14. The end effector according to Clause 12, wherein the position sensor is a first position sensor, and the end effector further comprises a second position sensor disposed on the electrode body and configured to output a current when receiving an electromagnetic field to detect the position of the electrode.

[0059] Clause 15. The end effector according to Clause 14, wherein the first position sensor and the second position sensor constitute a biaxial sensor.

[0060] Clause 16. An electrode assembly comprising: an electrode body extending along a longitudinal axis and defining a recess; an electrode cap at least partially disposed within the recess; and a spring member disposed within the recess between the electrode body and the electrode cap, the spring member being configured to expand the electrode cap outwardly from the electrode body.

[0061] Clause 17. The electrode assembly according to clause 16, further comprising a sensor coupled to the spring member, the sensor being configured to detect a force applied to the electrode.

[0062] Clause 18. The electrode assembly according to clause 16, wherein the electrode body further defines a lip extending around the recess, the lip being configured to prevent the electrode cap from being removed from the recess.

[0063] Clause 19. The electrode assembly according to clause 16, wherein the electrode body further defines a lumen configured to receive a spine, the spine being configured to support the electrode assembly.

[0064] Clause 20. The electrode assembly according to clause 16, further comprising a position sensor disposed on the electrode body and configured to output a current when subjected to an electromagnetic field to detect the position of the electrode.

[0065] Clause 21. The electrode assembly according to clause 20, wherein the position sensor is disposed on a side facing inwardly of the electrode body.

[0066] Clause 22. The electrode assembly according to clause 20, wherein the position sensor is a first position sensor, and the electrode further comprises a second position sensor disposed on the electrode body and configured to output a current when subjected to an electromagnetic field to detect the position of the electrode.

[0067] Clause 23. The electrode assembly according to clause 22, wherein the first position sensor and the second position sensor constitute a biaxial sensor.

[0068] Clause 24. The electrode assembly according to Clause 16, further comprising a first position sensor disposed on the electrode cap and a second position sensor disposed on the electrode body.

[0069] The above embodiments are cited as examples, and the present invention is not limited to what has been specifically illustrated and described herein above. Rather, the scope of the present invention includes both combinations and sub - combinations of various features described herein heretofore, as well as those variations and modifications thereof that would be contemplated by one of ordinary skill in the art upon reading the foregoing description and that are not disclosed in the prior art.

[0070] 〔Embodiment〕 (1) An end - effector for a medical device, A plurality of spines extending along a longitudinal axis and defining a basket assembly, the spines being bent radially outward from the longitudinal axis so as to define a radius of curvature with respect to the longitudinal axis and being configured to transition between an expanded configuration and a folded configuration, each spine of the plurality of spines including a section extending radially outward from the radius of curvature defined by the remainder of each spine. An end - effector comprising, for each spine of the plurality of spines, at least one electrode disposed on the section. (2) The end - effector according to Embodiment 1, wherein a plurality of electrodes are disposed on each spine of the plurality of spines. (3) The end - effector according to Embodiment 1, wherein each electrode of the plurality of electrodes is disposed on a respective section on each spine of the plurality of spines. (4) For each spine among the plurality of spines, the section of each spine is configured to contact each of the plurality of electrodes with the tissue before the remainder of each spine contacts the tissue when the end effector is brought into contact with the tissue, according to the end effector of embodiment 3. (5) The end effector according to embodiment 1, wherein the at least one electrode is configured to deliver ablation energy to the tissue.

[0071] (6) The end effector according to embodiment 3, further comprising a location sensor disposed on each respective section and configured to detect the position of the section. (7) The end effector according to embodiment 6, wherein each location sensor is disposed on the section under each respective electrode of the plurality of electrodes. (8) Each electrode is an electrode body, defining a lumen and a recess extending through the electrode body, an electrode body, an electrode cap at least partially disposed within the recess, and a spring member disposed within the recess between the electrode body and the electrode cap, the spring member being configured to expand the electrode cap outwardly from the electrode body, according to the end effector of embodiment 1. (9) The end effector according to embodiment 8, further comprising a force sensor assembly including a first coil coupled to the spring member and a second coil fixed to the electrode, the first coil sensor being configured to output a current in response to a magnetic field for determination of a force applied to the electrode. (10) The end effector according to embodiment 8, wherein the electrode body further defines a lip extending around the recess, the lip being configured to prevent the electrode cap from being removed from the recess.

[0072] (11) The end effector according to embodiment 8, wherein the lumen is configured to receive a spine among the plurality of spines. (12) The end effector according to embodiment 8, further comprising a position sensor disposed on the electrode body and configured to output a current when receiving an electromagnetic field to detect the position of the electrode. (13) The end effector according to embodiment 12, wherein the position sensor is disposed on the side facing the inside of the electrode body facing the longitudinal axis. (14) The end effector according to embodiment 12, wherein the position sensor is a first position sensor, and the end effector further comprises a second position sensor disposed on the electrode body and configured to output a current when receiving an electromagnetic field to detect the position of the electrode. (15) The end effector according to embodiment 14, wherein the first position sensor and the second position sensor constitute a biaxial sensor.

[0073] (16) An electrode assembly, an electrode body extending along a longitudinal axis and defining a recess, an electrode cap at least partially disposed within the recess, a spring member disposed within the recess between the electrode body and the electrode cap and configured to expand the electrode cap outwardly from the electrode body. (17) The electrode assembly according to embodiment 16, further comprising a force sensor assembly including a first coil coupled to the spring member and a second coil fixed to the electrode body, the force sensor assembly being configured to detect a force applied to the electrode. (18) The electrode assembly according to embodiment 16, wherein the electrode body further defines a lip extending around the recess, the lip being configured to prevent the electrode cap from being removed from the recess. (19) The electrode assembly according to embodiment 16, wherein the electrode body further defines a lumen configured to receive a spine, and the spine is configured to support the electrode assembly. (20) The electrode assembly according to embodiment 16, further comprising a position sensor disposed on the electrode body and configured to output a current when receiving an electromagnetic field to detect the position of the electrode.

Claims

1. An end effector for a medical device, comprising a plurality of spines extending along a longitudinal axis and defining a basket assembly, each spine of the plurality of spines being curved radially outwardly from the longitudinal axis so as to define a radius of curvature with respect to the longitudinal axis and being configured to transition between an expanded configuration and a folded configuration, each spine of the plurality of spines including a section extending radially outwardly from the radius of curvature defined by the remainder of the respective spine; and at least one electrode disposed on the section for each spine of the plurality of spines.

2. The end effector according to claim 1, wherein a plurality of electrodes are disposed on each spine of the plurality of spines.

3. The end effector according to claim 1, wherein each electrode of the plurality of electrodes is disposed on a respective section on each spine of the plurality of spines.

4. The end effector according to claim 3, wherein the section of each spine of the plurality of spines is configured to contact the tissue with each respective electrode of the plurality of electrodes before the remainder of each spine contacts the tissue when the end effector is brought into contact with the tissue.

5. The end effector according to claim 1, wherein the at least one electrode is configured to deliver ablation energy to tissue.

6. The end effector according to claim 3, further comprising a location sensor disposed on each respective section and configured to detect the location of the section.

7. The end effector according to claim 6, wherein each location sensor is disposed on the section under each respective electrode of the plurality of electrodes.

8. Each electrode comprises an electrode body defining a lumen and a recess extending through the electrode body; an electrode cap disposed at least partially within the recess; and a spring member disposed within the recess between the electrode body and the electrode cap and configured to expand the electrode cap outwardly from the electrode body.

9. The end effector according to claim 8, further comprising a force sensor assembly including a first coil coupled to the spring member and a second coil fixed to the electrode, wherein the first coil sensor is configured to output a current in response to a magnetic field for determining a force applied to the electrode.

10. The end effector according to claim 8, wherein the electrode body further defines a lip extending around the recess, and the lip is configured to prevent the electrode cap from being removed from the recess.

11. The end effector according to claim 8, wherein the lumen is configured to receive a spine among the plurality of spines.

12. The end effector according to claim 8, further comprising a position sensor disposed on the electrode body and configured to output a current when receiving an electromagnetic field to detect a position of the electrode.

13. The end effector according to claim 12, wherein the position sensor is disposed on an inner side of the electrode body facing the longitudinal axis direction.

14. The end effector according to claim 12, wherein the position sensor is a first position sensor, and the end effector further comprises a second position sensor disposed on the electrode body and configured to output a current when receiving an electromagnetic field to detect a position of the electrode.

15. The end effector according to claim 14, wherein the first position sensor and the second position sensor constitute a biaxial sensor.

16. An electrode assembly, comprising: an electrode body extending along a longitudinal axis and defining a recess; an electrode cap at least partially disposed within the recess; a spring member disposed within the recess between the electrode body and the electrode cap, the spring member being configured to expand the electrode cap outwardly from the electrode body.

17. The electrode assembly according to claim 16, further comprising a force sensor assembly including a first coil coupled to the spring member and a second coil fixed to the electrode body, the force sensor assembly being configured to detect a force applied to the electrode.

18. The electrode assembly according to claim 16, wherein the electrode body further defines a lip extending around the recess, and the lip is configured to prevent the electrode cap from being removed from the recess.

19. The electrode assembly according to claim 16, wherein the electrode body further defines a lumen configured to receive a spine, and the spine is configured to support the electrode assembly.

20. The electrode assembly according to claim 16, further comprising a position sensor disposed on the electrode body and configured to output a current when receiving an electromagnetic field to detect the position of the electrode.

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